3.
Solar Energy• Passive system: Collect heat from the sun, such as building a house with windows facing toward the sun.• Active system: Using solar collectors to provide heat.

4.
Geothermal Energy• Energy from the heat of the interior earth.• Water in rocks is heated by magma.• Energy has been trapped by drilling wills to reach the hot water.• Power turbines generate electricity from this energy.

5.
Energy by Water and Wind• Energy from Running Water – Hydroelectric energy is produced by running water. – Massive dams hold back running water and move it through the plant. – The force of water spins the turbines of electrical generators to produce electricity.

6.
Energy from Tides• The ocean waters that move into and away from the shore twice a day are called tides.• Dams are built to trap water at high tide and release water at low tides

7.
Energy from Wind• Propeller wind turbines, on wind farms, can produce enough energy for a whole community.• Only certain areas have enough wind for this to succeed (example: Bay area)